Yes with the correct thermostat and installer who knows what they are doing?..

Is there a thermostat that would work particularly well with that system? Are there compatibility issues I should be wary of? Can you describe how the package unit would do that (I’m looking to gain a little bit of education myself on this forum). Again, thanks for the reply and the information.

Tigerdunes, thanks for the info! I don’t know if the system has a variable speed blower and I was hoping that someone on this site would know by looking at the model number and year of manufacture. Is there a place I can go to find that out?

First of all, help yourself with your research and learn to use Google or another search engine. According to a quick look, you have not provided the complete model number. How do you heat your home?

what mdl/brand thermostat do you have now? Unfortunately, many dealers take nice equipment and cripple it with wrong thermostat or fail to set it up correctly to take advantage of unit's full features.

i would want Trane/AS thermostat 624 or 824.

TD

AmStd Package Unit

Looking at the the product data it appears this package unit does not have a variable speed blower. It has a multi speed fan with taps that can be set at 350, 400, and 450 CFM. The split for low and high cooling is 25,200 and 35,600 BTUs. That means in the low stage you can run at 70% capacity which is typical for a scroll compressor.

I would check the dip switch settings to see what air flow is selected. If your goal is better dehumidification, then try the 350 CFM setting. That with a properly wired 2-stage thermostat with a cool to dehumidify feature should give you better humidity control.

For Mike,

i think you are mistaken about the var speed blower motor. See page 5 under Indoor fan.

TD

Thanks for pointing that out, I missed that.

Does this packaged unit have a true definition of a variable speed motor? My thinking is variable speed means the thermostat can slow down the blower when in a cool to dehumidify condition. This is how the Carrier Infinity systems as well as other communicating type systems operate. In this case the speed of the motor can be varied but it is set once via the control board dip switches. The thermostat can only select the low and high stages with a fixed blower speed assigned to each stage.

I always thought this was known in the industry as multi-speed. But then again there is no strict definition and manufacturers are free to describe it in different ways. It makes it very confusing for buyers when selecting equipment.

tiger_dunes, of course I googled the topic (and found the same manual), but I'm not accustomed to reading HVAC manuals. The tone of your comment, "First of all, help yourself with your research and learn to use Google or another search engine" is not helpful.

The heating is natural gas, does that matter with respect to what type of blower is installed in the unit? I thought the SEER rating and the model # would have been enough to understand if it's capable of dehumidifying on demand.

I didn't assume that it has a variable speed indoor fan. Frankly, all the websites that I went to talk about multi-speed fans and variable speed fans with a multitude of different opinions. In my untrained world, a multi-speed fan sounds a lot like a variable speed fan, but apparently they're different.

I came to this forum to see if someone knows definitively and has had any experience with this unit and it's ability to dehumidify in conjunction with a thermostat that has a humidistat-type functionality.

If you have experience with the unit I'm talking about and setting it up to dehumidify, then by all means, let your knowledge flow forth.

If you don't, then please refrain from telling me how to educate myself with respect to search engines and google.

When it comes to variable speed blowers, the speed is typically decided by algorithmic timed sequences of the control board in which the variable speed fan motor is connected to.

I also suppose it's possible for some to be modulated by the controller that converts AC power to DC power to operate the motor.

The thermostat in nearly all cases of a non-communicating system merely sends the request for the blower to run.

If you have a two speed AC system, it is running (more or less) in dehumidify mode during 1st stage operation. Provided of course that the system is wired properly for 2 stage control. Some thermostats provide a dehumidify function, just realize there are limitations (it's not really a control, it's a function.)

IE: You can have 90%+ humidity at 60 degrees. No one is going to run the AC under those conditions. This is why humidity in relation to AC is a function, not a control.

Humidity and Temperature are independent from one another.

You can add a whole home dehumidifier to control humidity further, but that is a whole other conversation.

It is quite apparent that OP is not very knowledgeable about this package unit and I don't recommend for this homeowner to be changing dip switches. Call your installer.

IMO

You never identified the model of existing thermostat. I asked about the heating because it appears you have 2 stage heating. Therefore if you do decide to replace your old thermostat, you want a mdl that will control 2 stage heat based on demand, not a timer. Big deal!...will save you money...both the mdl thermostats that I suggested can handle DOD for humidity control and 2 stage heating as long as you gave a var speed blower motor which it appears you have from the spec sheet. I am curious why you haven't called your installing dealer to confirm your unit has var speed blower motor.

Good Luck!

tiger_dunes, you are correct, I don't have intimate knowledge and wouldn't ever do this myself.

The installer that installed it in 2009 passed away in 2010. I could put in a call, but i'm not sure it would get answered! :-)

I've recently had the ductwork replaced (originally from the mid 1990's) and asked the folks doing the work if the package unit was capable of dehumidification. They said they weren't sure and would have to check with the technical support folks from AmSt.

Not all installers are created equal and I'm simply trying to educate myself so that I can identify the good installers from the mediocre and below.

My current thermostat is a Honeywell, something like a RTH7600D, but I'm not 100% certain. It has no WiFi, but it's 7 day programmable and has a humidity readout.

Thanks for all your help.

It was never my intent to direct a home owner to start making changes to their system via dip switches, which is why I didn't refer to it as such.

With that said, there are plenty that will do it anyway and 9 times out of 10 make the situation worse and more costly to repair more often than not.

My goal was merely to high light, that the thermostat (most cases) is a dumb device that just blindly sends a signal to the smarter (more informed decision maker) of the system 'the furnace control board'.

However, not all control boards are much smarter than the thermostat and some thermostats (limited few, are quite intelligent --- usually the communicating kind --- for clarity I am not talking about the nest). So this depends on the system you have.

Austin Air Companie

thanks for the posts, I found them informative and helpful. I’m trying to build some knowledge so I can plan for my HVAC needs as an informed customer. I’ve found that not all HVAC companies are created equal. Your posts are definitely helping me. Thanks!

4YCZ6036A1075AB is the full model number. Bought in 2009.

For OP...just so you know, the 75 indicates 75 KBTUs input at 80% eff yielding 60 KBTUs output...this model is in the performance data that I provided link for recently...of course, this system has 2 stage heat, low and high stage...

IMO